The Mdr2 knockout mouse model is the first and so far only non-surgical animal model clearly showing the macroscopic (bile duct strictures and dilatations of the large bile ducts) and microscopic features (onion skin-type like pericholangitis and periductal fibrosis) of sclerosing cholangitis in humans [8,42]. Here, ABCB4 is linked to sclerosing cholangitis.